Page 703 - Workshop Manual - Tunland (2017)

DIAGNOSTICS - ENGINE CONTROL SYSTEM 04-17

READING AND CLEARANCE OF THE DIAGNOSTIC TROUBLE 04

CODE (DTC)
CAUTION

Failures are detected by the engine control system and stored in the engine control
module (ECM), and the system failures may be current or historic ones.

1 . Current failures: It refers to the failures currently existing in ECM, for example:
open circuit of engine coolant temperature sensor.The current failures must be
repaired; otherwise, they cannot be cleared from the memory.
2 . Historic failures:They may be stored in 2 modes:
• The failures had been repaired, the actual failures do not exist, however the
memorized data are not cleared from ECM.
• Failures had occurred but do not exist presently, however, they might reoccur.
For example: poor contact of harness. Since the stored failures are not the
present failures, they require no repair before they are cleared from the memory,
or they may be handled as per the elimination of intermittent failures.

CAUTION

• If the battery voltage is too low and the testing codes of ECM cannot be output
normally, the battery voltage must be detected before the check, and the voltage
shall not be lower than 11V.
• When the battery or ECM connector is disconnected, the failure codes stored
in ECM may be cleared.
• Before the KT600 intelligent diagnostic apparatus is connected or disconnected,
the ignition switch must be set to its OFF (LOCK) position.

CAUTION

Use a special-purpose test tool to read the engine failure codes: KT600 comprehensive
intelligent diagnostic apparatus.
Use a diagnostic apparatus to perform DTC reading procedures.

1 . Check and ensure the following conditions:
• Throttle is completely closed.
• Air conditioner switch is set to its OFF position.
• Transmission is set to its neutral gear.

2 . Switch off the ignition.
3 . Connect the analyzer to the diagnostics connector (16-pin) at the lower left of
the dashboard.
4 . Switch on the ignition and the analyzer - use the latest software version.
5 . Select menu items: According to vehicle configuration, select the operation to
read the fault code.
6 . Check, record and delete the DTC and data stream (in case DTC cannot be
deleted, implement diagnostic steps as per “the check list of failure codes”,
and repair the failure).
7 . Start the engine until it reaches normal working temperature.